Here are the definitions according to the Mule Barn:
Mule: A domesticated, hybrid animal that results from crossing a mare (female horse) and a jack (male donkey).
Donkey: A domesticated ass.
Which, of course, begs the question "What is an ass?" Thankfully, Mule Barn also provides a definition of this particular animal.
Ass: A four-footed, hoofed mammal related to the horse, but smaller, with longer ears and a shorter mane, shorter hair on the tail, and a dark stripe along the back.
So, it seems the aforementioned jackass is simply a male ass. The main difference between the jackass and the donkey is their domestication -- the ass is wild; the donkey is domesticated.
But what about the burro? Turns out that the burro is a small donkey that is often used as a pack animal because it is particularly sure-footed.
GOT you now don't I. DONKEY. Like I said all along Spook. I am married, thereby making me DOMESTICATED so I cannot possibly be or hung like a JACKASS but I can be and am hung like a....Say it with me now everyone....DONKEY!!!!
PS RU12NVME cannot be held responsible for having entirely too much time on his hands at this moment to perform this sort of research for a mere giggle. WHACKO I tell you.